jhopper408

I don't even know what your talking about logging the car! I guess I'm not hip to the lingo.

neutron82

datalog, like hptuners or something like that... it sees everything that's going on and saves the info so you can see if there are any issues... it could be knocking and pulling timing and that's why it feels like you are losing power all due to bad gas or the tune could be aggressive and on the edge and along with the combination of bad gas and hot/humid weather could cause it to knock... not saying that is exactly your issue it's just an idea and something I would personally check

jhopper408

I totally agree with ya. That's exactly what it seems like! Thanks for putting up with my 1970s knowledge. Lol. But I think your totally correct. And I will take action.

spdislife

I've used a number of different brands and have never been able to tell the difference in performance.

Solofast

So long as the octane rating is there you won't likely be able to tell any difference when putting in a tankful..

That said there is a big difference in the additive packages and how long your car runs well. It's more of a maintenance thing. After a lot of running on crummy gas you will have more deposit buildup on the intake valves and in the injectors and the car will eventually run like crap.

My C4's would have injector clogging and run rough in a few tanks of some brands of gas and would clean right up and run properly when fed a tank or two of gas with a more detergent in it. Tried all kinds of injector cleaners and snake oils, but in those days Amoco mid grade had the highest amount of detergent in it and it cleaned up and ran better than even their premium. I was at a race an talked to an Amoco engineer and mentioned my experience and he said that they put (in his words) "a ton of detergent" in their mid grade fuel, even more than in their premium. I asked why and he said they wanted the customer to "feel the difference" in how much better their car ran on a tank of mid grade and that would keep them coming back and using the more expensive fuel. They figured that the premium users weren't going to get the buildup in the first place, so they didn't need as much cleaner in the higher octane stuff. I ran the mid grade during the week and when I went to race on the weekend I'd use the premium...

The more sophisticated injection systems of the C5 and later aren't as prone to injector clogging as the older cars, but keeping the injectors clean really helps performance. You only have one O2 sensor per bank and it is tuning to the worst cylinder. If your injectors are flowing the same that means that some cylinders aren't rich and others lean and the car runs stronger and more efficiently.

slsnider423

Here in New Mexico, the highest octane you can get is 91. I haven't noticed any difference in performance from brand to brand. I usually get my fuel at Sam's Club! All 3 of my 'Vettes run just fine....two Z06's and one '99 Convertible.

Solofast

I did notice the other day when filling up at Costco that they have "Top Tier" fuel in their premium. That is their premium additive package meet Top Tier standards and is by definition good stuff...

ArmchairArchitect

I only use gas that meets Top Tier standards (easy to find), it's better at all grades/octanes, and usually Top Tier gas stations are the same price on average as crap-tier gas.

List of brands that meet Top Tier standards:
http://www.toptiergas.com/licensedbrands/

The GasBuddy website and app can show you the Top Tier stations with the best prices near your location (just add the Top Tier as a search filter):
www.gasbuddy.com

KnightDriveTV

You must've been searching and came upon this thread. It's a dead thread from 2015 but...all good...no reason the talk can't continue...lol!